Dish washer

ABSTRACT

The washing chamber of a dishwashing machine is divided in two zones, one for dishes, glasses and the like, the other for metallic saucepans and the like; the jets of solution in both zones are fed from the same source, and the jets in the first zone are closed automatically when the temperature of the solution reaches a certain degree, so that the solution is successively sprayed at a higher temperature and higher pressure only on the metallic saucepans.

United States Patent [72] Inventor Lamberto Mam Pondenone, Italy [21]Appl. No. 847,166 [22] Filed Aug. 4, 1969 [45] Patented June 22, 1971[73] Assignee lndustrieA. Zamml S.p.A.

Pordenone, Italy [54] DISH WASHER 6 Claims, 9 Drawing Figs.

[52] US. Cl. 134/57, 134/95,134/103,134/1l5,134/183 51 Int. Cl 1108b3/02 [50] Field of Search 134/56 D, 57 D, 57 DL, 58 D, 58 DL, 94,95,103,115,182, 183, 200

[56] References Cited UNITED STATES PATENTS 3,217,721 11/1965 Hertel134/115X 3,230,961 1/1966 Bankert et al. 134/115 X 3,253,784 5/1966 Longet a1. 134/176 UX FOREIGN PATENTS 1,380,262 10/1964 France 134/2001,500,537 9/ 1967 France 134/200 90,554 11/1967 France 134/115 PrimaryExaminer-Robert 1.. Bleutge Attorney-Holman, Glascock, Downing andSeebold ABSTRACT: The washing chamber of a dishwashing machine isdivided in two zones, one for dishes, glasses and the like, the otherfor metallic saucepans and the like; the jets of solution in both zonesare fed from the same source, and the jets in the first zone are closedautomatically when the temperature of the solution reaches a certaindegree, so that the solution is successively sprayed at a highertemperature and higher pressure only on the metallic saucepans.

PATENTEUJUNZZIBYI 3,586,011

sum 2 OF 3 lllllllllll IHHIII ll L Jl 316 INVENTOR 315 14078097: @0120MQM ,D I 1- DISII WASHER This invention relates to a dish washer able towash in a differentiated manner according to the nature of the dishes.In particular the machine according to this invention permits crockeryof the type comprising plates, tumblers, cups and general delicatearticles of porcelain, ceramic and glass on the one hand, and saucepans,cutlery and metallic articles on the other hand, to be washed atdifferent temperatures in keeping with the nature of the articlesthemselves.

It is known that in conventional dishwashers a single basket is providedsuitably arranged for the loading both of porcelain, ceramic and similararticles, and metallic articles, in order to use rationally, both theavailable washing space and the washing efficiency of the spray jets atthe same time.

It is also known that because of the difference in resistance to washaction of the articles loaded in the basket, it has been necessary toadopt compromise solutions with regard to the temperature of the washspray solution, concentration of detergent in it and mechanical force ofthe washing jets. In fact the most delicate articles such as glass onlystand up with difficulty to strong impacts and excessive thermal shockcaused by successive washing and rinsing which often cause breakage orcracking.

When chemical action of the detergent is added to the temperatureefiect, there easily arises color fading in articles such as ceramic orporcelain decorated plates.

It is thus clear that the temperature of the wash solution may notsupercede a certain limit, which is normally about 65 C. On the otherhand saucepans for the most part require a more energetic action ofwashing because of the particular nature of the dirt (incrustations,residual carbon deposits due to excess heat), which is strongly anchoredto the saucepan surfaces.

In general it can be said that with the above-mentioned solutionscomprising compromise of temperature, detergent concentration andmechanical jet action, a satisfactory and adequate wash is obtained forarticles such as plates, tumblers and cups, i.e. those into which foodsare placed or from which they are consumed, while the degree of wash isinsufficient for cooking receptacles.

Machines have also been tried in which mechanical wash action has beenincreased by increasing the power of jets and similar solutions, butwithout obtaining the results expected. From the point of view of thedetergent, there is an optimum concentration in the wash solution beyondwhich there is no corresponding increase in wash efficiency. Evenresorting to more energetic detergents has been shown to be useless, asit results in a deterioration of colors and decorative designs onceramic objects and the like. In other solutions the special arrangementhas been adopted of providing two loading baskets, one for delicatearticles such as plates, tumblers cups and the like, and another forsaucepans.

However the temperature and detergent concentration in the wash solutionhave been maintained unchanged for the above-mentioned reasons, and themechanical force of the jets acting on the saucepans has been increased.

Finally machines have already been proposed with two separate washchambers for the delicate objects and saucepans respectively, withsuitable connecting pipework controlled by values controlled by aprogram selector, so as to carry out the wash as required, either alonein one of the two chambers or in both chambers simultaneously. In thislatter case the chambers can be connected in series or in parallel. Thissystem gives a certain economy of operation in that it allows a singlewash chambers to be put into operation and to reuse the wash waterdischarged from one chamber for a further wash cycle in the otherchamber. But even this solution does not take account of thesubstantially different requirements of delicate articles on the onehand and saucepans on the other, the temperature and detergentconcentration in the wash solution being maintained unchanged.

The dishwasher according to this invention substantially eliminates thedisadvantages cited above and gives satisfactory washing both ofdelicate articles and saucepans. For this object the present inventioncomprises two separate zones in a dishwasher into which the delicatearticles such as plates, tumblers, cups and the like, and saucepans areloaded respectively, each of said two zones being provided with at leastone sprayer and interception means which interrupt the feed of washsolution to the separate zone containing said delicate articles onattaining a preset temperature while continuing heating at the washsolution and its feed to the separate zone containing said saucepans.Consequently with the dishwasher according to the invention it ispossible to carry out a wash of the normal type satisfactory fordelicate articles, and then to subject the saucepans to a wash of moreintense action with the wash solution at a higher temperature while atthe same time excluding said more delicate articles from the directaction of the wash solution at higher temperature.

It should further be observed that according to this invention saiddelicate articles can be contacted by steam from the wash solution ofhigher temperature and hence be subjected to partial sterilization.

The main advantage of this invention is that of subjecting saucepans tothe action of a wash solution at a temperature higher than that normallyprovided and hence to a more energetic thermochemical action on theresidues and dirt anchored to the saucepan.

A further important advantage is that the result described in thepreceding paragraph is attained simply and economically by a single washcircuit. A further advantage which will be clear following thedescription is that the separation of the two said zones is reduced to aminimum, its only purpose being to impede contact between the hotterdetergent solution and the delicate articles.

A further advantageous prerogative of the invention provides for meansfor adjusting the pressure down stream of the pump feeding the washsolution, simultaneously with said means for intercepting the feed ofthe solution to the zone containing the delicate articles. In particularin a preferred embodiment a bypass is provided between the suction anddelivery of the pump, suitably dimensioned and controlled by a valuewhose movement opens and closes communication between said bypass andthe pump delivery to the spray swivels.

Further objects and advantages of the dishwasher according to theinvention will better appear from the description which follows ofcertain preferred embodiments illustrated by way of example in theaccompanying drawings in which:

FIG. 1 is a simplified diagrammatic view of the wash chamber and thewash circuit of the dishwasher according to the invention;

FIG. 2 is a view analogous to FIG. I of another embodiment of thedishwasher;

FIG. 3 is a view analogous to FIG. 2 of a further embodiment;

FIGS. 4 and 5 show another embodiment in two different conditions of theinterception means;

FIGS. 6 and 7 are views analogous to FIGS. 4 and 5 of a still furtherembodiment of the dishwasher according to the present invention;

FIG. 8 shows diagrammatically the wash chamber and the means for feedingand adjusting the wash solution;

FIG. 9 shows a variation of the embodiment of FIG. 8.

It is to be observed that in the various embodiments shown in thedrawings, all those parts of the dishwasher which are conventional andwithout interest in the understanding of the present invention have beenomitted for clarity.

Referring first to FIG. 1, a wash tank 10 of a dishwasher is shown whoseinternal cavity is subdivided into two zones 11 and 12 by a separationbaffle 13 that can be suitably secured to the housing of the tank 10.The collection sump 14 for the detergent solution is provided in thebase of the tank, and its discharge line comprises a conduit 15connected to the suction of a circulation and wash pump 16.

Each zone II and 112 is provided with at least one sprayer, 117 and MIrespectively, having spray nozzles for wash solution which direct jetsof solution on to the articles contained in the corresponding zone.

The rotating sprayers I7 and 118 are fed by the pump 16 by way of twodelivery conduits I9 and 20.

The conduit 20 which feeds wash solution to the zone I2 containing themore delicate articles such as plates, tumblers, cups and the like, isprovided with an interception member namely a valve 271 which cuts offthe feed to the one I2 at any desired moment during the wash cycle.

The machine of FIG. I operates in the following way:

After having loaded the various objects to be washed in theircorresponding zones on a suitable support and basket and after apossible prewash phase and heating, the actual wash is commencedsimultaneously in the two zones, by feeding detergent solutions to therotating swivels l7 and 118 through two conduits I9 and 20.

After a certain period of time necessary for washing the more delicatearticles, determined for example by the action of a thermostat, thetemperature of the detergent solution during this period reaching about60 C., the valve 211 is operated so cutting off feed to the zone I2 andsimultaneously the temperature of the solution is increased to about 85C. using suitable conventional means, while washing continues of thesaucepans contained in zone Ill.

After termination of this wash period and after discharge of the washsolution the normal cycle of rinsing etc. is resumed in each zone.

It is clear that in this way the initial wash phase provides for theelimination of residues and dirt which are less firm, while the secondperiod provides a more energetic action directed solely against thefirmer and more resistant dirt.

FIG. 2, in which corresponding reference numerals increased by MW toindicate parts corresponding to FIG. 11 have been used, illustratesanother embodiment in which the two zones III and 1112 are superimposedand the baffle I113 is horizontal instead of vertical.

In this case the articles contained in zone I112, are struck only bysteam from the detergent solution sprayed into the underneath zone 1111during said second wash period.

The embodiment illustrated in FIG. 3 is analogous to that of FIG. 2(corresponding parts being indicated by equal numerals furnished with aprime), with the exception that the two feed conduits I19 and 120' arecoaxial, the valve 121 is arranged so as to intercept feed to theconduit 120', and the baffle 11113 is incorporated in the swivel I I8.

This embodiment may be advantageous in view of the compactness of thedishwasher.

FIGS. 43 and show a further embodiment (parts equal to those of FIG. Ibeing indicated by equal numbers increased by 200) in which a louvermember 222 is substituted for the interception valve 21, and which inthe position shown in FIG. 4 permits spraying of the articles containedin the chamber 2H2, while in the condition shown in FIG. 5 it interceptssaid spraymg.

Similarly the FIGS. 6 and 7 (in which parts similar to those of FIG. 5are indicated with equal numerals increased by 100) show a similarembodiment in which however the zones 3M and 3112 are superimposed.

In this case the lower interception member 322 functions also as abaffle and the feed conduit from the pump 316 is single, serving bothsprayers.

It is clear that the interception member, whether this be the valve 21,I121 or 11211 of FIGS. I, 2 or 3, or the louver member 222 or 322 ofFIGS. 6, 5 or 6, 7, is controlled for intercepting the feed of washsolution to the zone containing delicate articles at the appropriatemoment during the wash cycle by means of any suitable control member butin all ways as a function of the temperature which the wash solution hasreached at that moment, for example by means of the timer programmer ofthe dishwasher or a thermostat.

In FIG. S (in which the same reference numerals as in FIG. II butincreased by 400 are used) the dishwasher comprises a wash tank 4lll0whose internal cavity is subdivided into two zones MI and M2 by aseparation bafi'le 4II3 suitably secured preferably to the housing ofthe tank M0. The base of the tank is provided with the collection sumpM4 for the wash solution, the discharge line from which consists of aconduit 415 connected to the suction of a circulation and wash pump 416.

Each zone 4111, 4112 is provided with at least one rotating swivelsprayer, 417 and 4118 respectively, having spray nozzles for washsolution, which direct jets of solution on to the articles contained inthe corresponding zone. The sprayers 417 and 418 are fed by way of aconduit 4519 in which a double valve is seated comprising two mobilemembers 430 and 431i controlled by an electromagnet. The two members434) and 131 are seatable on seats 433 and 434 and are linked by a stem435 so that they operate simultaneously. Further a bypass 336 isprovided in the conduit 4115. In the condition shown in FIG. 3 both thesprayers 4517 and 4118 are being fed, and the member 430 closes theentrance to the bypass 41-36, which consequently does not form part ofthe flow circuit for the wash solution. When at an appropriate point inthe wash cycle the feed to the sprayer acting in zone 4112 isinterrupted by closing the valve member 4311 against the seat 434 thenthe bypass is opened by withdrawal of the valve member 430 from the seat433 and part of the wash solution from the pump is returned upstream. Itis clear that by suitably sizing the bypass 4136 the pressure is reducedto the most suitable value for washing the pans alone.

In the embodiment of FIG. 9 in which like members to FIG. 8 areindicated with like reference numerals increased by 1100, a three-wayvalve placed in the feed line 520 to the upper swivel 5113 substitutesthe members 430 and 431, and its third way is connected to the bypass536, the other end of which is connected to the suction of the pump 516.In this case when feed to the swivel 538 is intercepted and hence to thezone 5E2, all the corresponding wash solution feed is passed through thebypass see because of which the feed pressure through the conduit 5 I9remains unaltered.

A further variation not illustrated in the drawings comprises a basketdivided into two zones for the purpose already mentioned by a separationbaffle, at least one sprayer rotatable about its own axis being rigidwith each zone, the feed line to the sprayer rigid with the zonecontaining plates, tumblers and the like being provided with aninterception member in the same manner as previously described.

An advantage worth noting from the economical and constructional pointof view is that the baffles and louver interception members can beconstructed of any suitable material, for example plastics materialresistant to the conditions arising during wash.

It should also be observed that the separation baffle between the twowash zones, particularly, when it is horizontal, must not divide the twozones hermetically in order to permit drainage of water from the upperzone and circulation of ventilation air.

What we claim is:

l. A dishwasher, both domestic and industrial, in which the wash chamberis subdivided by a baffle into two wash zones for the loading ofdelicate crockery such as plates, earthenware and the like and theloading of cooking pans respectively, each of said zones being providedwith at least one sprayer, the sprayers being fed by a single wash pump,and in which an interception member is provided controlled by athermostat which senses the temperature of the wash solution in order toexclude the flow of solution heated above a predetermined temperature tothe delicate crockery in said corresponding zone.

2. A dishwasher as claimed in claim I, in which said pump feeds saidsprayers through parallel tubes and said interception member is situatedin the tube which feeds the sprayer or sprayers provided for the zoneintended for washing delicate crockery.

tion pump for adjusting the delivery pressure of the solution.

6. The dishwasher as claimed in claim 5, in which said adjusting meanscomprise a bypass with its extremities connected respectively to theupstream and downstream sides of said wash solution feed and circulationpump, and a controlled valve for opening and closing communicationbetween the delivery of said pump and the corresponding extremity ofsaid bypass.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO.3,586,011 DATED June 22, 1971 |NVENTOR(S) Lamberto Mazza It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

[30] Foreign Priority Data:

Italian Appln. No. 19925 A/68 filed August 7, 1968 Italian Appln. No.25681 A/68 filed December 28,

Signed and sealed this 6th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Comissioner of Patents Arresting Officerand Trademarks

1. A dishwasher, both domestic and industrial, in which the wash chamberis subdivided by a baffle into two wash zones for the loading ofdelicate crockery such as plates, earthenware and the like and theloading of cooking pans respectively, each of said zones being providedwith at least one sprayer, the sprayers being fed by a single wash pump,and in which an interception member is provided controlled by athermostat which senses the temperature of the wash solution in order toexclude the flow of solution heated above a predetermined temperature tothe delicate crockery in said corresponding zone.
 2. A dishwasher asclaimed in claim 1, in which said pump feeds said sprayers throughparallel tubes and said interception member is situated in the tubewhich feeds the sprayer or sprayers provided for the zone intended forwashing delicate crockery.
 3. A dishwasher as claimed in claim 1, inwhich each sprayer of the zone for washing delicate crockery is providedwith an interception member which moves between two positions, in one ofwhich it intercepts the jets of solution issuing from the sprayer. 4.The dishwasher as claimed is claim 1, in which said baffle onlypartially divides the wash chamber.
 5. The dishwasher as claimed inclaim 1, in which means are provided downstream of the wash solutionfeed and circulation pump for adjusting the delivery pressure of thesolution.
 6. The dishwasher as claimed in claim 5, in which saidadjusting means comprise a bypass with its extremities connectedrespectively to the upstream and downstream sides of said wash solutionfeed and circulation pump, and a controlled valve for opening andclosing communication between the delivery of said pump and thecorresponding extremity of said bypass.